Mesomorphic properties of resorcinol

Abstract It is believed that hydrogen bonds to a great extent determine the polymorphism of resorcinol. In order to understand this more deeply, complementary studies of ambient pressure polymorphism of high-purity resorcinol were carried out by Differential Scanning Calorimetry (DSC), Polarizing Optical Microscopy (POM) and Transmitted Light Intensity (TLI), together with X-ray diffraction. Temperature-dependent infrared spectroscopy studies of this compound involved two-dimensional analysis. The present study delivers complex insight into the evolution of the vibrational spectra upon phase transitions, covering the whole range of frequencies. New results on thermal stability and the influence of thermal history upon the phase transitions are reported. The equilibrium geometries, vibrational frequencies, and infrared intensities were additionally computed using the Density Functional Theory (DFT) with semi-empirical dispersion corrections, for hydrogen-bonded aggregates of resorcinol molecules.